TONER FOR DEVELOPING ELECTROSTATIC CHARGE IMAGE AND TWO-COMPONENT DEVELOPER

摘要

PROBLEM TO BE SOLVED: To obtain a developer preventing the lowering of image density and the increase of fog by stabilizing the quantity of electric charges on a toner independently of an environmental change over a long period of time and suppressing the charge-up of the toner especially in an environment at low temp. and humidity. SOLUTION: Colored resin particles contg. a colorant and polyester bonding resin are mixed with fine powder having a smaller average particle diameter than the colored resin particles to obtain the objective negative charge type toner for developing an electrostatic charge image. The fine powder is obtd. by multistage emulsion polymn. In a stage before the final stage, alkyl acrylate and/or alkyl methacrylate is polymerized or copolymerized. In the final stage, polymerizable carboxylic acid or polymerizable carboxylate is polymerized.